Major depressive disorder is common in the elderly medically ill. The recent NIMH Consensus Report on Depression in Late Life emphasizes the need for research in this area. Depressive disorder could be a final common pathway in a variety of disease states. However the reason for depression in each of these conditions could be different. Major depression is particularly common in patients with coronary artery disease or hypertension. The proposed study seeks to look at possible causes for depression in elderly patients with coronary artery disease and/or hypertension. Previous studies have demonstrated that patients with coronary artery disease/or hypertension often exhibit ischemic changes in the brain. These changes are seen on magnetic resonance imaging of the brain as signal abnormalities called leukoencephalopathy, deep white matter hyperintensities and subcortical hyperintensities. These changes have also been related to the occurrence of depression in the elderly. We have developed a model relating these changes in the brain, psychosocial factors and severity of illness to the development of depression in this population. The proposed study will provide an understanding of the role of social supports, life events, severity of illness, religious coping behavior and neuroanatomical changes in the pathophysiology of depression and provide a basis for treatment and prevention approaches for depression in this population.